Tool retainer



Nov. 6, 1928.

E. w. STEVENS TOOL RETAINER Filed March 15, 1926 INVENTOR. Edward W 51eve/7s ATTORNEY.

Patented Nov. 6, 1928.

UNITED STATES PATENT OFFICE.

EDWARD W. STEVENS, OF DETROIT, MICHIGAN, ASSIGNOR TO CHICAGO PNEUMATIC TOOL COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

TOOL RETAINER.

Application filed March 15, 192G.' Serial No. 94,684.

This invention relates to percussive machines, such for example as pneumatic hammers, and more particularly to devices for retaining the working tool in proper position in the machines and for conveniently permitting interchange of tools when de: sired. It specifically relates to tool retainers of the sleeve type arranged for telescoping engagement with the machine and retained thereon by suitable latching blocks projecting through slots in the retainer sleeve which blocks are ordinarily mounted on an arcuate flat spring seated in an annular recess on the exterior of the sleeve. A retainer of this type is disclosed in my copending ap plication SeriaPNo. 652,369, filed July 18, 1923, and the present invention is in the nature of an improvement upon the same.

It has been found in practice that tool retainers of the described type occasionally fail as a result of loss of tension in the spring which supports the latching blocks or as a result of the breakin" of the spring so that the blocks drop oif tlie retainer sleeve. In either event the sleeve becomes loose and is free to be forced from the percussive machine along with the working tool in case of accidental operation with possible destruction of property and'injury to persons.

Among the objects of the invention are to providean improved retainer of the described type which can be securely locked to the percussive machine, to prevent release of the retainer sleeve in the event of breakage or loss .oftension of a spring, to provide locking means for a retainer sleeve quickly movable to locking or releasing position, and in general to improve prior devices in the interest of more eflicient and satisfactory service. v I

In order to illustrate the invention one concrete embodiment thereof is shown in the accompanying drawings in which:

Fig. 1 is a side elevational view of a pneumatic hammer equipped with the invention.

Fig. 2 is a fragmentary horizontal sectional view on an enlarged scale, substantially on the line 2-2 of Fig. 1.

Fig. 3 is a transverse sectional view on the line 33 of Fig. 2.

The invention is illustrated as applied to the end of the cylinder of a pneumatic hammer A for the purpose of retaining 1n opera-- tool such as a rivet or button set B, which as disclosed in Fig. 2 is provided with a shank 6 extending within the open end of the hammer cylinder A and with an annular stop flange b.

The retainer comprises a sleeve 4 of substantial length, the inner or rearward portion of which is adapted to telescope over the outer end of the hammer cylinder A and is provided upon its interior with a stop shoulder 5 engaging a portion of the cylinder. The outer end of the retainer sleeve extends beyond the cylinder and is provided at its outer extremity with an inwardly disposed annular flange 6 which cooperates with the flange b of the working tool B to prevent the latter from being discharged from the percussive machine but permitting limited axial movement of the working tool. A cushioning member such as a spring C may be interposed between the flanges 6 and b of the retainer and of the working tool respectively. The inner or rearward end of retainer sleeve 4 is provided upon its exterior with an annular groove 7 providing annular shoulders, between which or seated in said .groove is an arcuate spring or open ring 8 carrying latching blocks 9 which'may be integral with ring 8 or secured thereto as by rivets 10. Blocks 9 extend through openings or slots 11, in sleeve 4, disposed within groove 7, which blocks are adapted to engage transversely milled slots or recesses be similarly inclined. The retainer as here- 9 tofore described is substantially identical with that disclosed in my aforesaid copending application and is applied toand re moved fromthe hammer cylinder in the same manner.

The means by which the above described retainer may be positively looked "upon the hammer cylinder A, and to which the present invention particularly relates, will now be described. A locking member 13 is mounted upon retainer sleeve 4 so as to be movable axially of the sleeve into a position which will positively prevent the with drawal of the latching blocks 9 from their slots 11 in sleeve 4. The preferred form of which member 13. is that of ,a locking ring or nut having screw threaded engagement with the rear portion of sleeve 4:, as shown, and provided with an internally counterbored part 13' adapted to extend partly over spring 8 and blocks 9 in one osition of nut 13-, as shown in full lines in ig. 2, so that it is impossible for locking blocks 9 to be withdrawn in any manner from engagement in grooves 12 of cylinder A. When the retainer is to be applied to a hammer cylinder or to be removed therefroin the locking ring 13 is rotated so as toback it ofi" of sleeve 4 to the dotted line position shown in Fig. 2 whereupon the latching blocks 9 are free to move in and out of their slots 11 as the retainer sleeve is forced over the end of the cylinder when applying it or partly rotating on the cylinder to remove it therefrom.

From the above it will be apparent that the present invention provides locking means ositively prevent removal of a retainer s eeve even if the spring carrying the circling at least a portion of said sleeve, 1

latching blocks is broken, that the locking ring or nut also prevents rotation of the sleeve upon the cylinder which wouldotherwise serve to release the sleeve, and that the locking means herein disclosed is simple and easily manipulated when working tools are to be interchan ed and not subject to failure under the bar usage and abuse to which devices of this type are subjected.

' While but one form of the invention has been herein shown and described, it is to be understood that the invention is not limited to the specific details thereof, but covers all changes, modifications and adaptions within the scope of the appended claims.

I claim as my invention:

1. The combination with a percussive machine and a working tool to be actuated thereby, of a retainer for releasably maintaining said tool on said machine said retainer engaging said tool and having spring pressed members engaging said machine, and a threaded member projectable over said first named members to prevent releasing movement of the latter.

2. The combination with a percussive machine of a retainer sleeve in telescoping en gagement with said machine, a spring enlocking blocks on said spring projecting through slots in said sleeve and arranged to be forced into latching position relative to 5 said machine by said spring, and a locking nut on said sleeve movable axially thereof into a position over said blocks positively to prevent withdrawal of said blocks from blocks for engagement with said machine,

and a locking nut on said sleeve having a portion projectable over said blocks positively to hold said blocks against releasing movement.

4. A tool retaining device for a percussive machine comprising a retainer sleeve arran ed for telescoping engagement with the mac ine, a spring ring on the exterior of said sleeve, latching means on said ring projecting through a slot in said sleeve to engage said machine, and locking means on said sleeve projectable over said latching ineans to prevent releasing movement of the atter.

5. A tool retaining device for a percussive machine comprising a retainer sleeve arranged for telescoping engagement with the machine, a. spring ring on the exterior of said sleeve, a latching member on said ring projecting through a slot in said sleeve to.

engage a recess in said machine, and a looking ring having threaded engagement with the exterior of said sleeve and movable ta a position over said first named ring thereby to prevent releasing movement of said latching means. I L l 6. A tool retainer for power hammers comprising a retainer sleeve arranged for telescoping engagement with the hammer cylinder, said sleeve having anannular recess on its exterior, an arcuate spring ring encirclin said sleeve and seated in said recess, latc ing blocks carried by said ring and projecting through slots in said sleeve to engage recesses in the hammer and a locking nut having screw readed engagement with said sleeve adjacent said ring and having a part projectable over said blocks to prevent releasing movement of the same.

. Signed at Detroit, Michigan, this 11th. da of March, 1926.

EDWARD W. STEVENS.

c linder iii CERTIFICATE OF CORRECTION.

Patent No. 1,690,559. v Granted November 6, i928, to

EDWARD W. STEVENS.

it is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, line 57, ciaim 2, strike out the words "axially thereof"; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this llthday of December, A. D 1928.

. M. J. Moore, (Seal) Acting Commissioner of Patents. 

